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06 BF150 overheating at idle

M

mark123

Member
at idle it overheats and the alarm activates, if the engine is running 2000 + it runs fine but sometimes the alarm activates at wide open throttle. New water pump, both new thermostats. This problem occured with new and old thermostats and water pump. The poper thermostats are in the proper locations and not upside down etc... powerhead anodes were always changed and never really got that corroded. pick-up tube is clear. Pisser is pissing. Relief valve is clean . Is there any way to check water pressure, where would you tap into the system and what should the specs be? Any other ideas. This is in salt water, and the same occurs in a tank or in the bay.
 
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Tuff to diagnose, and don't want to be bearer of bad news. Mount case has rotted out where exhaust exit's. You would have to tear down to verify. Also be certain that it is heat and not the ole low oil pressure trick. Check to see if top pully is rubbing on crank posision sensor. If so your toast. Thanks Martin
 
It is my brother in laws boat, the alarm is doing long intermittent beeps, going through the service manual I found that this cannot be an overheating alarm, fuel and filters are good (no water) dealer came out and scanned some codes and then erased them and ran the engine, same thing happened and no codes came up. Dealer is new without much experience and they don't know what to do next.


mcyama said:
Tuff to diagnose, and don't want to be bearer of bad news. Mount case has rotted out where exhaust exit's. You would have to tear down to verify. Also be certain that it is heat and not the ole low oil pressure trick. Check to see if top pully is rubbing on crank posision sensor. If so your toast. Thanks Martin
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What codes did it throw off originally? Overheating is a continuous alarm. Do you have the four light key panel? If so, what lights are on and which are off when you get the long intermittent alarm? Typically, the long intermittent alarm signals a problem with the programmed fuel injection system. If you have the four light panel, and the green oil light is on and the red MIL (check engine) light is on, and the other two lights remain off, when the alarm is sounding, then it is a fuel or fuel injection problem.

When the alarm goes off, is the fuel pump-up bulb still firm? If it is soft, try pumping it when the alarm goes off. If that stops the alarm, it may be your low pressure fuel pump. If the bulb is partially collapsed, open your gas tank filler cap. If the alarm stops after a minute or two, your gas tank breather tube is clogged up. Use a long wire to open it up. I believe that engine also has a high pressure fuel filter, if the above doesn't fix the problem, replace that filter.

BTW - where is the boat? When you say "the bay" is that the Chesapeake? If so, I can probably direct you to a reputable, experienced dealer in your area.
 
When I said the bay I meant Tracadie Bay http://maps.google.ca/maps/place?ft...ed=0CAwQ-gswAA&sa=X&ei=i6olUJ2NCImNxQG5hoGgAQ
If you have ever eaten Prince Edward Island mussels there is a good chance they came from here, this problem is on a mussel boat. Anyway now the alarm is continuous, (it was long intermitten). You can hear bubbling/gurgling and it comes and goes. It seems as though it loses it prime, overheats and then starts pumping again. Mcyama mentioned "Mount case has rotted out where exhaust exit's" what has to be disassembled in order to check this? The pee stream is continous. Also the green light is on and the red light is on on the control and he said the red light is the temp indicator, the other 2 lights are not on.


chawk_man said:
What codes did it throw off originally? Overheating is a continuous alarm. Do you have the four light key panel? If so, what lights are on and which are off when you get the long intermittent alarm? Typically, the long intermittent alarm signals a problem with the programmed fuel injection system. If you have the four light panel, and the green oil light is on and the red MIL (check engine) light is on, and the other two lights remain off, when the alarm is sounding, then it is a fuel or fuel injection problem.

When the alarm goes off, is the fuel pump-up bulb still firm? If it is soft, try pumping it when the alarm goes off. If that stops the alarm, it may be your low pressure fuel pump. If the bulb is partially collapsed, open your gas tank filler cap. If the alarm stops after a minute or two, your gas tank breather tube is clogged up. Use a long wire to open it up. I believe that engine also has a high pressure fuel filter, if the above doesn't fix the problem, replace that filter.

BTW - where is the boat? When you say "the bay" is that the Chesapeake? If so, I can probably direct you to a reputable, experienced dealer in your area.
Click to expand...
 
Okay - good that you have a four light consol switch. So we will assume you have an overheat problem based on the continuous alarm and just the red overheat light is on. It's strange that no codes are being thrown from the ECM.

There is a way to check water pressure, but I'm not sure how it is done on your engine. On my 225 there is a recessed hexhead bolt near the top of the water jacket.

Often when an old impeller is changed out, pieces have broken off and lodge in the cooling system. Not that familiar with the 150, but there is a typical protocol for diagnosing overheat problems - from easy to harder...

1. Pull the water intake screens on the bottom of the lower unit, inspect, and clean. Look for any blockages inside. (It's amazing how often this simple item is overlooked.)

2. Pull off the cover and while the engine is running, thoroughly inspect all water hoses and connections for leaks.

3. Pull the t-stat(s) and test in a pot of water on the stove. Your owners manual should tell you what the initial opening temp and full open temps should be. Also, make sure the t-stats open wide enough, per the manual. (For the 225 beginning opening is approx 140F, full open is approx 160F, and open distance is 3 mm.)

4. While the t-stats are removed flush the water passages using a water hose with as much pressure as you can get. Typically I use a nozzle fully open, tightly wrap a rag around it, seal it into the t-stat opening by hand pressure,and turn the water on full force.

5. If there is a water relief port (usually a recessed hex head bolt), remove and install a water pressure gauge and take the reading at idle and check against spec's. If it is too low, you likely have an impeller or blockage problem before the port. ft it is too high, you likely have a blockage after the port.

6. If all that fails, then drop the lower unit and inspect impeller. To be safe, replace the entire water pump. It's not that much more than the impeller kit, and fairly easy to do.

 
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